A car-mounted network is provided on a vehicle for the sake of performing various controls in a vehicle. The car-mounted network is realized by connecting a lot of Electronic Control Units (ECUs), sensors, actuators or the like to a LAN. Hereinafter, an Electronic Control Unit (ECU), a sensor, an actuator or the like that are connected to the car-mounted network is referred to as a “communication node”. The communication nodes can be disposed in various places in the vehicle. The communication nodes are connected by communication wires or electric cables.
Patent Document 1: Japanese Laid-Open Patent Application No. 2008-113339